Dredge digging structure



Oct. 31, 1950 E. VON BOLHAR DREDGE- DIGGING STRUCTURE Filed oci. 25,1946- 3 Sheets-Sheet 1 &

IN VEN TOR. fogar Vania/bar 1950 E. VON BOLHAR DREDGE DIGGING STRUCTURE3 Sheets-Sheet 3 Filed Oct. 25, 1946 INVENTOR.

fc/yar 1 0 W Patented ca. 31', 1950 UNITED STATES PATENT OFFICE DREDGEDIGGING STRUCTURE Edgar von Bolhar, Sausalito, Calif., assignor to YubaManufacturing Company, San Francisco, Calif., a corporation ofCalifornia Application October- 25 1946, Serial No. 705,730

4 Claims. 1

My invention relates to'alluvial dredges and more particularly to thedigging units and associated structures of alluvial dredges.

In the type of alluvial dredge referred to there is provided a main hullon which the digging ladder is mounted. The ladder extends between anupper tumbler and a lower tumbler around which is trained a diggingchain incorporating digging buckets. As dredging structures of this typehave been developed they have increased greatly in size so that thedigging mechanism has become increasingly bulky and of greatly increasedweight. The problems of manufacture and of handling the largerstructures have become more complex.

It is therefore an object of my invention to provide a dredge diggingstructure in which the bucket and related parts are of an improveddesign more readily manufactured and operated and more especiallyadapted to massive units.

Another object of the invention is to provide a dredge digging structurein which the stresses and resulting strains in the several parts aremore readily met or resisted by especially adapted materials. 7

Another object of the invention is to provide a generally improveddredge digging structure.

These objects and others are attained in the embodiment of the inventiondisclosed in the accompanying drawings in which Figure 1 is a partiallydiagrammatic view in cross section on a vertical plane through a dredgepond showing an alluvial dredge in operation, portions of the figurebeing broken away.

Figure 2 is a side elevation of an upper tumbler of the dredge with thediggin structure encompassing the tumbler, some parts bein broken away.

Figure 3 is a fragmentary view, for the most part being a cross sectionthe plane of which is indicated by the line 33 of Figure 2.

Figure 4 is a fragmentary view in cross section the plane of which isindicated by the line 4-4 of Figure 2'.

Figure 5 is an isometric perspective of a link body constructed inaccordance with the invention together with some associated partsdisplaced for clarity of illustration from their normal positions.

In its preferred form, the dredge diggin structure of my inventioncomprises a link body including a central plate having a central boss atone end thereof and a pair of lateral bosses at the other end thereofjoined by side flanges depending from the central plate and eachincorporating a pair of apertured side bosses there, in. The centralboss and lateral bosses are de signed to interfit on adjacent structuresand are held for articulated relationship by bucket pinspiercing thevarious bosses and turning in bushings. The pins are retained by capswhich engage suitably formed recesses in them and in the lateral bosses.Adapted to cooperate with the link body is a bucket body'including ahood for retaining material and having a bottom wall and a pair of sidewalls. Projecting from each of the side walls is a pair of aperturedlugs depending below the bottom wall to straddle the side bosses on thelink body. To secure the bucket body and the link body together, pinspierce the apertured lugs and side bosses and are suitably held inplace.

While there are many environments in which, my dredge digging structurecan be satisfactorily- -and successfully operated, it is especiallyadapted rection, as seen in Figure 1', by appropriate driving machinery,not shown.

Mounted on the digging ladder ii! at the lower or outboard end thereofis a lower tumbler l8 mounted for free rotation. The tumblers I! and [8receive a continuous chain digging mechanism 2! engaging the uppertumbler for driving energy and the lower tumbler for support in aposition adjacent the actual digging site. The upper run 22 of thedigging mechanism is supported at intervals on the ladder l2 by a spacedroller idlers 23 whereas the lower run 24 preferably hangs by gravity ina catenary curve or in some instances where the Weight is very great,the lower run 24 is supported on an idler pulley, not shown herein.

The entiredigging chain is advanced uniformly over the tumblers and overthe supporting idlers 23 and is effective to dislodge material 26 fromthe bank 8, to carry'it on the upper run 22 and then to discharge itinto appropriate handling and value-saving machinery, not shown, on thedredge hull 6. g

The dredge digging chain is comprised of a 3 plurality of individualunits joined together for relative pivotal motion about transverse axesand since the numerous units are all identical, a description of one ofthem applies equally to the others. Each unit or digging structureincludes a link body 5| fabricated in any of various diiferent ways fromsuitable material preferably a metal capable of withstanding rather hightensile stresses. Each of the link bodies 5| is subjected to the load ofa large part of the assemblage and hence is especially constructed towithstand the resulting severe forces.

The link body includes a relatively planar plate 52 extendingsubstantially parallel to the general direction of the chain run. It isprovided adjacent one end with an integral, circular cylindrical,central boss 53 approximately tangent to the top of the central plate 52and extending transversely for something less than the full width of theplate. At its other end the central plate is divided to merge with apair of lateral bosses 5d and 55 formed integrally with the centralplate and having a circular cylindrical contour substantially the sameas that of the central boss 53 of the next adja cent link and to formsubstantial continuations thereof.

In order that the central boss 53 and the cooperating lateral bosses 54and 55 can be suitably jointed with respect to each other, there isprovided a through pin 51 extending from the outer extremity of the boss54 to the outer extremity of the boss 56. The pin in this instancebecause of its relatively large diameter is tubular and is of agenerally symmetrical configuration thus distinguishing markedly frommost previous dredge bucket pins which are formed with turned headsthereon. The pin 5! is held in position both axially and againstrotation by being formed at each end with a diametral cross slot 58 inalignment with or merging with a similar pair of notches 59 and 6| inthe lateral bosses 5t and 55. When the pin 51 is in position andproperly rotated, the slot 58 and notches 59 and 51 align to provide acontinuous groove.

Seated in the groove is a diametral key 62 projecting from the innerface of a cap disc 63 overlying the outer edge of one of the lateralbosses 5t and 5B. recess 5 to receive the enlarged head of a throughbolt and nut assembly 56 effective to secure the adjacent members inassembled relationship. When the bolt 55 is disassembled by removal ofits nut and is withdrawn from its assembled position, the cap 53 can beremoved, the pin 5! can be withdrawn and then the adjacent link bodiescan be separated.

To improve the articulated joint, the interior of the central boss 53 isprovided with a bushing El bearing upon the pin 51 and removed when wornand replaced to prolong the effective life of the structure. With thearrangement as so far described, there is afforded a compact, strong,relatively light link body in itself capable of withstanding the variousstresses to which it is subjected in its working environment. While thelink body illustrated herein is shown as cast in one piece, it can asreadily be fabricated of a number of separate pieces permanently weldedtogether. Both of these types of construction are referred to herein asintegral link body structures.

In either case the link body is preferably provided with a centralaperture 58 to reduce its This disc is provided with a weight and toafiord access to the under side of the plate 52 and is further extendedlaterally by ledges 69 and I0 projecting from the lower portion of apair of side flanges H and 12 which are downturned from the plate 52 andextend between the bosses 53, 54, and 56. The ledges are edged withreenforcing walls 13 and are further braced by brackets 14 and 1'5 sothat weight upon the central plate is well distributed to the bearingledges 69 and 75. The depending side flanges H and 72 acts asstiffener-s for the plate 52 and also assist in maintaining the variousbosses against distortion and relative displacement.

In accordance with the invention there is likewise provided a bucketbody 8| adapted to cooperate with the link body 5!. The body 8| must becapable primarily of withstanding a good deal of abrasion and roughcontact with rocks in the soil and is not in this design called upon towithstand any large amount of tensile stress so that it preferably iscast as an integral structure of manganese steel. The bucket body 8|includes a bottom wall 82 smoothly merging with a pair of side walls 83and 84 having a somewhat hemispherical contour of the type customaryindredge buckets. Preferably the bottom or back 82 terminates in agenerally planar portion disposed parallel to but spaced from thecentral plate 52.

In order to mount and secure the dredge bucket body, the side walls 83and 84 are each provided with a pair of projecting lugs 86 and Bl. Theseare spaced apart in a fore and aft direction on the bucket body and alsoare laterally spaced apart enough to straddle the central plate 52. Thelugs 85 and 81 are provided with reenforcing flanges 88 and 89 andterminate in bosses 99 and SI of an extent and position to overlie andregister with comparable bosses 93 and 94 projecting from the flanges Hof the link body. In assembled relationship of the link body and bucketbody the various bosses are in alignment.

Each of the bosses is pierced to accommodate afastening pin 96 seated inthe bosses but not extending across the central portion of the bucketand link assembly. Each of the pins 95 has an enlarged head 97 formedwith a central depression 98 to receive either the head of a throughbolt 99 or a nut fill at the extremity thereof and effective to hold apair of the pins 98 in position. With this arrangement the principalloads are transmitted between the bucket body and the link body byshearing stresses on the pins although some of the lateral forces aredirectly transmitted in compression between the bosses 99 and 9! and thebosses 93 and 94. In any case the severe tensile stresses on the link 5|are not transmitted to the bucket body 8|.

With this arrangement, upon the removal of the nut IOI and the throughbolt 99 and upon the withdrawal of the pins 96, the bucket body 81 canreadily be lifted from the link body 5| and an entirely new bucket cantake its place being quickly locked into position by reinstallation ofpins 96 and the through bolts 99 and the nuts IOI. In this fashiondifferent buckets eifective under diiferent soil conditions can beutilized with the same chain structure and without necessitating theinterruption of the continuity of the chain structure. In fact bucketsof varying difi'erent shapes and functions can be incorporated readilyin the same chain device. Under certain circumstances it is morefeasible to restore or replace entire bucket body as semblies than it issimply to relip or to replace detachable lips on the buckets as is nowoften the practice. By following the present invention there is affordeda considerably improved dredge digging structure, one especially capableof use in large size devices and one in which advantage can be taken ofvarious different materials of engineering in resisting mostadvantageously the various stresses to-which the device is subject inoperation.

I claim:

1. A dredge digging structure comprising an integral link body having acentral plate, downturnedside flanges on said central plate andtransversely apertured side bosses on said side flanges, an integralbucket body having a material holding hood and transversely aperturedside lugs projecting downwardly from said hood, and transverse fastenersengaging said side lugs and said side bosses for holding said link andsaid body together.

2. A dredge digging structure comprising an integral link body includinga central plate, a substantially circular cylindrical central boss atone end of said central plate, a pair of substantially circularcylindrical lateral bosses at the other end of said central plate, sideflanges depending from said central plate and extending between saidcentral boss and respective ones of said lateral bosses, the margins ofsaid side flanges being substantially tangent to the respective bossesand apertured side bosses on said side flanges below said central plate.

3. A dredge digging structure comprising an integral link body includinga central plate, a central boss at one end of said central plate, a pairof lateral bosses at the other end of said central plate, side flangesdepending from said central plate and extending between said centralboss and respective ones of said lateral bosses, a pair of aperturedside bosses on each of said side flanges; an integral bucket bodyincluding a hood having a pair of side walls, a bottom wall, a pair ofapertured lugs depending from each of said side Walls below said bottomwall to straddle 6 said side bosses; and means for securing said linkbody and said bucket body together including pins engaging said sidebosses and said lugs.

4. A dredge digging structure comprising an integral link body includinga central plate, a central transverse boss depending from said centralplate at one end thereof, a pair of transverse lateral bosses dependingfrom said central plate at the other end thereof, side flanges dependingfrom said central plate and extending between said central boss andrespective ones of said lateral bosses, a pair of side bossesincorporated in each one of said side flanges, said side bosses havingtransverse apertures therethrough below said central plate; an integralbucket body including a hood having a pair of side walls and a bottomwall, a pair of lugs depending from each of said side walls below saidbottom wall to straddle said side bosses, said lugs having transverseapertures therein disposed to align with said apertures in said sidebosses when said bucket bottom wall is located just above said centralplate; and fastening pins disposed in said aligned apertures.

EDGAR VON BOLHAR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 297,202 Orran Aug. 20, 1878622,637 Russell Apr. 4, 1899 994,487 Vaichis June 6, 1911 1,084,662Porter Jan. 20, 1914 1,560,370 Bennett Nov. 3, 1925 1,638,099 RorabeckAug. 9, 1927 1,838,362 Clark Dec. 29, 1931 2,319,979 Collins May 25,1943 FOREIGN PATENTS Number Country Date 146,813 Great Britain Nov. 7,1921 559,458 France June 15, 1923

